Collator folder register assembly

ABSTRACT

An improved folder assembly for folding a gather or plurality of sheets along a predetermined fold line includes a plurality of inclined feed and folder rollers. Front and side registers position the gather in a predetermined relationship with the folder rollers while the gather is supported on an inclined surface. The gather is then folded along the predetermined fold line by the folder rollers. A trimmer assembly having a single movable knife is operable to trim the folded gather to its final size in a single trimming operation.

Uni ates tom [72] Inventors Carl ll. l-ileigl Westlnlte; lfieith S. Macey, Rocky River, both of Ohio Appl. No. 834,122 Filed June 17, 1969 Patented Dec. 14, 11971 Assignee ll-larris-lntertype Corporatlon Cleveland, Ohio Continuatlonln-pnrt of application Ser. No. 738,031, .llune W, W68, now Patent No. 3,55%,531. Thls application .lune l7, R969, Ser- No. 8%,1122

COlLlLA'lOR FOLDER REGHSTIER ASSEMBLY l7 Clalmns, ll Drawing Figs.

US. Cl 270/68 A Int. Cl Etifili 45/l4l Field of Search 270/68, 68

1 was [56] lRelleren ces (Filed UNITED STATES PATENTS 2,249,186 7/1941 Spiess 270/68 A 2,766,569 10/1956 Strother 61 a! 270/63 A UX 3,150,871 /1964 Boblil et al. 270/63 A 3.178,l7l 4/l965 Springer et al 270/68 A Primary Examiner-Robert W. Michell Assistant Examiner-L. R. Oremland Attorney-Yount and Tarolli to its final size in a single trimming operation.

COLLATOR FOLDER REGISTER ASSEMBLY This application is a continuation-in-part of our copending application Ser. No. 738,031, filed June 18, I968, now US. Pat. No. 3,554,531 and entitled Binder Assembly.

The present invention relates generally to an apparatus for folding and trimming a plurality of sheets of material.

The binder assembly disclosed in our aforesaid copending application has a sloping or inclined support surface along which a plurality of sheets of material or gathers are moved. During this movement the gathers are either saddle, side, or corner stitched at a stitching station. Each of the stitched gathers is then moved in turn to an inclined folder assembly which is operable to fold saddle stitched gathers. Each folded gather is then trimmed to its final size by a single trimming operation along the face or open front edge portion of the gather.

To enable a folded gather to be trimmed in a single operation it is necessary to have the fold almost precisely aligned with a predetermined fold line. Accordingly, the leading edge portion of the gather is moved into engagement with front stops to position or register the gather relative to folder rollers immediately before the gather is folded by passing between these rollers. Due to the inclination of the folder mechanism, the leading end portion of the gather tends to droop or move downwardly while the gather is being registered relative to the folder rollers. This downward movement or droop results in the fold being out of alignment with the predetermined fold line so that the gather can not be trimmed to the desired configuration in a single trimming operation.

Accordingly, it is an object of this invention to provide a new and improved assembly for folding and trimming a gather while it moves along a path which is inclined relative to a horizontal plane.

Another object of this invention is to provide a new and improved folder mechanism having registering means for registering both the leading and lower side edge portions of a gather relative to rollers for folding the gather.

Another object of this invention is to provide a new and improved assembly for folding a gather along a predetermined fold line and trimming the gather to its final size with a single cutting operation which is performed only along the open face or front portion ofthe gather.

Another object of this invention is to provide a new and improved assembly for folding and trimming sheet material, the assembly including front and side register means for positioning a gather in a predetermined relationship with a pair of folder rollers so that the gather is folded along a predetermined fold line and a single movable knife which is operable to trim the folded gather to its final size in a single trimming operation.

These and other objects and features of the invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a partially broken away and inclined schematic illustration of a folder and trimmer assembly illustrating a specific preferred embodiment of the invention;

FIG. 2 is a schematic illustration depicting the feeding of a gather or plurality of sheets into the folder and trimmer assembly ofFlG. 1;

FIG. 3 is a schematic illustration of the relationship between feed and folder rollers, a registering assembly for positioning a gather in a predetermined relationship with the folder rollers, and a single knife for trimming folded gathers to their final size;

FIG. 4 is a schematic plan view, taken along the line 4-4 of FIG. 1, further illustrating the register assembly;

FIG. 5 is an exaggerated schematic plan view illustrating the relationship between a gather and the register assembly of FIG. 4 when the register assembly is in a condition enabling the leading end of the gather to droop or move downwardly so that a predetermined fold line is misregistered relative to the folder rollers;

FIG. 6 is an exaggerated schematic illustration of a folded gather which was misregistered relative to the folder rollers in the manner illustrated schematically in FIG. 5;

FIG. 7 is a schematic illustration, similar to FIG. 5, of a gather being properly registered relative to the folder rollers;

FIG. 8 is a schematic illustration, similar to FIG. 6, of a folded gather registered in the manner illustrated schematically in FIG. 7;

FIG. 9 is a schematic illustration, taken generally along the line 9-9 of FIG. 8, depicting the relationship of a trimline to the face or open front edge portion of the folded gather of FIG. 8;

FIG. 10 is an exaggerated schematic illustration depicting the misregistering of a gather by raising the leading end portion of the gather too far with a side register assembly; and

FIG. II is an exaggerated schematic illustration, similar to FIG. 6, depicting a folded gather which was misregistered in the manner illustrated schematically in FIG. lit).

The present invention provides a folder and trimmer assembly having inclined rollers for folding a gather along a predetermined fold line. The folder assembly includes front and side registers which engage the leading and lower side edge portions of the gather, while it is supported on an inclined surface, to position or register the gather relative to folder rollers. The side register is adjustable to compensate for variations in the extent to which different gathers tend to droop or move downwardly along the inclined support surface due to differences in the physical characteristics of the gathers. Once a gather has been folded along a predetermined fold line, it is trimmed to its final shape by a single trimming operation along its face or open edge portion. This trimming operation is performed in one stroke of a single movable knife.

A combination folder and trimmer assembly 20, depicting specific preferred embodiment of the present invention is schematically illustrated in FIG. 1 and includes a folder assembly 22 and a trimmer assembly 24. Saddle stitched sheets or gathers 26 are moved along an inclined support surface 28 (FIG. 2) to the folder and trimmer assembly 20 in the manner fully disclosed in our copending application Ser. No. 738,031 filed June 18, 1968 and entitled Binder Assembly. As a group of sheets or gather 26 is moved along the inclined support surface 28 toward the folder assembly 22, upper and lower side edge portions of the gather are engaged by guides 32 and 34 to align the gather with an inclined feed nip 38 formed between an inclined feed roller 40 and an inclined folder roller 42. The longitudinal axes of the feed and folder rollers 40 and 42 are inclined at the same angle relative to a horizontal plane as is the support surface 28, in a specific preferred embodiment of the invention this angle is 30". Of course, the support surface 28 and rollers 40 and 42 could be inclined at other angles relative to the horizontal plane.

The folder assembly 22 is of the buckle folder type and includes a registering assembly 46 having; front register stops or members 48 against which the leading; edge portion 50 (see FIGS. 3 and 4) of a gather 26 is driven by the operation of the rollers 40 and 42. Engagement with the front register stops 48 causes the gather 26 to buckle in a known manner. Continued operation of the rollers 40 and 42 moves the buckled portion of the gather toward an inclined fold nip 54 (FIGS. l and 3) formed between the folder roller 42 and cooperating folder roller 56 which is parallel to the folder roller 42. The inclined folder rollers 42 and 56 fold the gather along a predetermined fold line as the gather passes through the nip 54. As it emerges from the nip 54, the folder gather is deflected by a plate 60 toward a nip formed between a pair of feed rollers 62 and 64. The folder gather is then moved into the trimmer assembly 24 by feed rollers 66 and 68. The feed rollers 62-68 and the trimmer assembly 24 are inclined at the same angle as the support surface 26 and folder rollers 42 and 56.

The trimmer assembly 24 is operable to trim the folded gather to its final size in a single trimming operation which is performed along the face or open front portion of the gather. This trimming operation is performed by a single movable knife 72 which is reciprocated relative to an inclined fixed knife 74 by a drive mechanism 76 (FIG. 1) to trim the folded gather along the predetermined fold line. Stop members 78 (FIG. 3) are moved in timed relationship with the knife 72 to engage the now leading back or folded end portion of the gather to position the now trailing face edge portion of the gather with the trim line directly beneath the movable knife 72. The gather is then trimmed to its final size by a single downward stroke of the knife 72-. Since the fixed knife 74 is inclined at the same angle as are the folder rollers 42 and 56, the stroke of the movable knife 72 is along a path which extends generally perpendicular to the inclined support surface 28 (FIG. 2) and the axes of the folder rollers. The front stops are then moved to the retracted position shown in dashed lines in FIG. 3 and the folded and trimmed gather is transferred to a suitable receiving station.

The register assembly 46 includes an arcuate gather supporting member or basket 82 which supports unfolded gathers as they are moved into engagement with the front register stops 48 by the operation of the rollers 40 and 42. The basket 82 is inclined relative to a horizontal plane at the same angle as the support surface 28 and the folder rollers 42 and 56. Therefore, when a leading edge portion 50 of the gather 26 engages the front register stops 48, the gather tends to droop or sag downwardly under the influence of gravity in the manner illustrated schematically in FIG. 5.

This downward drooping or movement of the leading edge portion 50 of the gather 26 results in the gather being misregistered relative the folder rollers 42 and 56. Due to this misregistration, the predetermined fold line 84, which is coincident with the stitch line on which staples 86 are located, is angularly displaced relative to the nip 54 of the folder rollers 42 and 56 by an angle indicated at 90 in FIG. 5. The nip 54 between the folder rollers 42 and 56 is inclined at the same angle with the horizontal plane as is the basket 82 and the folder rollers 42 and 56 (see FIG. 1). Therefore, the angular displacement of the predetermined fold line 84 causes the gather 26 to be folded along a fold line 91 which is angularly displaced relative to the predetermined fold line 84.

The head and tail edge portions 94 and 96 (FIG. 6) of the misregistered gather 26 are misaligned. Therefore, the improperly folded gather 26 can not be trimmed to a desired final size or configuration by a single trimming operation along the predetermined trim line indicated at 98 in FIG. 6. The improperly folded gather 26 will have to be squared-up by being trimmed along the head and tail edge portions 94 and 96 as well as along the trim line 98.

A side register or guide assembly 102 cooperates with the front register stops 48 and the basket 82 to effect proper registration of an unfolded gather 26. The side register assembly I02 includes a side register or guide plate 110 which extends perpendicularly to a support surface 111 on the basket 82. The side register plate 110 engages the lower side edge portion 112 to the gather 26 to prevent the gather from drooping or moving downwardly (FIG. 7). Therefore, the leading edge portion 50 of the gather 26 squarely engages front register stops 48 and the predetermined fold line 84 is positioned in a generally parallel relationship with the fold nip 54. This results in the gather 26 being folded along the predetermined fold line 84 as the gather passes through the fold nip 54 so that the head and tail edge portions 94 and 96 of the gather 26 are squared-off in the manner illustrated in FIG. 8. The properly folded gather 26 can be trimmed to its final size in a single trimming operation along the face or open front portion 114 of the gather (FIG. 9). This single trimming operation is performed in one stroke of the movable knife 72.

A long gather formed of a lightweight sheet material is relatively flexible and tends to droop or sag downwardly (FIG. 5). A short gather of relatively heavy sheet material is comparatively inflexible and does not tend to droop or sag downwardly to the same extent as does a relatively flexible gather. To compensate for differences in the physical characteristics of different size gathers, the side register plate 110 is adjustable transversely relative to the basket 82.

When a gather 26 is relatively flexible, the side register plate may have to be moved inwardly toward the upwardly sloping support surface 111 of the basket 82 so that the leading end portion of the flexible gather is pushed slightly upwardly. Under certain operating conditions, it may even be necessary to tilt or cock a relatively flexible gather 26 upwardly, in a manner similar but less extensive than that illustrated schematically in FIG. 10, to align the predetermined fold line 84 with the fold nip 54. However, if the gather 26 is relatively inflexible, the side register plate 110 is adjusted to the position illustrated in FIG. 7 to align the predetermined fold line 84 of the relatively inflexible gather 26 with the fold nip 54. It should be noted that if a relatively inflexible gather 26 is registered with the side plate 110 in the position illustrated in FIG. 10, the predetermined fold line 84 will be angularly displaced relative to the fold nip 54. Therefore the gather 26 will be folded in the manner illustrated schematically in FIG. 11 and the head and tail edge portions 94 and 96 of the folded gather will have to be trimmed along with the face edge portion 114.

To facilitate adjustment of the register assembly 46 to accommodate different sizes of gathers, the side register plate 1 10 is mounted on guide rods or shafts 124 and 126 which are connected to an adjusting screw 128 by cross piece 129 (FIG. 4). The adjusting screw 128 is rotatable by means of a knob 130 to move the side register plate 110 inwardly and outwardly along an inclined path extending generally parallel to the inclined support surface 111 ofthe basket 82. The front register stops 48 extend into slots 131 in the basket 82 and are mounted on a pivotal crossbar 132 (FIG. I) to enable the front register stops to be adjusted in a known manner to register gather 26 of different lengths.

Feed and folder rollers which cooperate to form nips through which the gathers 26 pass are adjustable relative to each other to enable the folder assembly 22 to be used to fold gathers of different thicknesses. To this end, a plurality of eccentrics 134 (FIG. 1) are associated with mountings 138 for the rollers to enable them to be adjusted to vary the nip pressure between cooperating rollers. In the illustrated embodiment of the invention, the rollers are driven by a chain drive 140 which is located between the ends of the rollers and the frame 144 of the assembly 20.

As is more fully explained in our copending application Ser. No. 738,031, the binder assembly associated with the folder and trimmer assembly 20 is selectively operable to either side, comer, or saddle stitch gathers. Generally speaking, side and corner stitched gathers are not folded. Therefore, a gate or guide is mounted for pivoting movement between the deflecting position in which saddle stitched gathers are directed downwardly into the basket 82 (see FIGS. 1 and 3) and a bypass position (illustrated in dashed lines in FIG. 3) in which side and corner stitched gathers are blocked against entering the fold nip 54. When the gate 150 is in the bypass position, side or corner stitched gathers are fed by the rollers 40 and 42 directly to a conveyor assembly 154 (FIG. 3) which transports them to a suitable receiving location.

In view of the foregoing description, it can be seen that the folder assembly 22 includes a registering assembly 46 having front stops 48 for registering the leading edge portion of a gather 26 relative to the folder rollers 42 and 56. In addition, a side register or guide plate 110 is provided for registering the lower side edge 112 of a gather 26 relative to the folder rollers 42 and 56 while the gather is supported on the inclined surface 111. This registration of both the leading and side edge portions 50 and 112 of the gather 26 relative to the nip 54 between the folder rollers 42 and S6 insures that the gather is folded along the predetermined fold line 84 in a manner illustrated in FIG. 8. Therefore, the gather can be trimmed to its final size in a single stroke of movable knife 72 which cooperates with the fixed knife 74 to trim the folded gather 26 along the trim line 98.

Although a buckle-type folder assembly 22 has been illustrated herein, it is contemplated that the folder assembly 22 could be of the knife type. Knife-type folders are well known and include a pair of inclined folder rollers, similar to the inclined folder rollers 42 and 56, which would cooperate to fold a gather in a known manner. Of course, the leading and side edges of the gather would have to be registered relative to the folder rollers of a knife-type folder in order to insure that the fold would be along a predetermined fold line so that the gather could be trimmed to its final size by a single trimming operation in the manner previously explained.

Having disclosed a specific preferred embodiment of our invention, the following is claimed:

1. An assembly for folding sheets along a predetermined fold line extending between side edge portions of the sheets in a generally parallel relationship with leading and trailing edge portions of the sheets, said assembly comprising a plurality of folder rollers cooperating to define a nip and having their longitudinal axes inclined relative to a horizontal plane whereby one side edge portion of the sheets is lower than the other side edge portion when the sheets pass between said folder rollers, feed means for moving the sheets to and from the nip formed by said folder rollers, and registering means for arresting movement of a leading edge portion of the sheets prior to movement of the sheets through the nip formed by the inclined folder rollers, for registering the sheets with the predetermined fold line extending generally parallel to the inclined longitudinal axes of said folder rollers, and for maintaining the predetermined fold line generally parallel to the inclined longitudinal axes of the folder rollers as the sheets enter the nip formed by the folder rollers, said registering means including a sheet support surface inclined relative to the horizontal plane at substantially the same angle as are the inclined longitudinal axes of said folder rollers, said inclined support surface including a trailing edge portion dispbsed adjacent to the nip formed by said folder rollers, a leading edge portion spaced further from said folder rollers than said trailing edge portion of said inclined support surface, and upper and lower side edge portions extending between said leading and trailing edge portions of said inclined support surface, said leading and trailing edge portions of said inclined support surface having longitudinal axes extending generally parallel to the inclined longitudinal axes of said folder rollers, said registering means further including front register means having a front register surface extending substantially perpendicularly from said leading edge portion of said inclined support surface for arresting movement of the leading edge portion of sheets as they are moving along said inclined support surface under the influence of said feed means, and side register means including a side register surface extending substantially perpendicularly from said lower side edge portion of said inclined support surface at a location intermediate the longitudinally extending axes of the leading and trailing edge portions of said inclined support surface for engaging the lower side edge portion of the sheets at a location which is between the predetermined fold line and the leading edge portion of the sheets when the sheets are on said inclined support surface to maintain the predetermined fold line generally parallel to the longitudinal axes of said folder rollers as the sheets are fed to the nip formed by the folder rollers and adjustment means for moving said side register surface relative to said support surface to adjust said side register means to position sheets of different physical characteristics on said inclined support surface in such an orientation that as the sheets pass through the nip formed by the inclined folder rollers a fold is formed along the predetermined fold line.

2. An assembly as set forth in claim ll wherein said feed means comprises a plurality ofinclined feed rollers positioned with their longitudinal axes extending generally parallel to the inclined longitudinal axes of said folder rollers.

3. An assembly as set forth in claim ll wherein said adjustment means includes means for moving said side register sur face along a path extending generally parallel to the inclined longitudinal axes of said folder rollers.

4. An assembly as set forth in claim 1 wherein said feed means is operable to move the leading edge portion of the sheets into engagement with said front register means with sufficient force to effect a buckling of the sheets along the predetermined fold line and to move the buckled portion of the sheets into a nip defined by said folder rollers.

5. An assembly as set forth in claim 1 further including cutter means for trimming the folded sheets along only their face edge portion.

6. An assembly as set forth in claim 5 wherein said cutter means includes only one movable knife and means for reciprocating said one movable knife through a stroke having a longitudinal axis extending generally perpendicular to the inclined longitudinal axes of said folder rollers.

7. An assembly as set forth in claim 6 wherein said cutter means further comprises a fixed knife for cooperating with said one movable knife, said fixed knife extending generally parallel to the inclined longitudinal axes of said folder rollers.

8. An assembly for folding sheets along a predetermined fold line extending between side edge portions of the sheets in a generally parallel relationship with leading and trailing edge portions of the sheets, said assembly comprising a base, folder means operatively connected with said base and rollers having their axes inclined relative to a horizontal plane and defining a nip for forming a fold in the sheets along the predetermined fold line when the sheets pass through the nip, feed means operatively connected with said base having first means for feeding sheets to said folder means, register means for positioning the sheets with the predetermined fold line in a predetermined relationship with the nip in said folder means to thereby facilitate the forming of the fold along the predetermined fold line, said register means including a register surface positioned to be engaged by an edge portion of the sheets as the sheets enter the nip in said folder means to position the sheets in the predetermined relationship with the nip in said folder means, and trimmer means operatively connected with said base for trimming the folded sheets to their final size with a single cutting operation which is performed only along the face edge portion of the folded sheets, said feed means including second means for feeding the folded sheets from said folder means to said trimmer means, said trimmer means ineluding only a single movable knife and means for reciprocating said single knife relative to said base to trim the folded sheets to their final size with only one stroke of said knife.

9. An assembly as set forth in claim 8 further comprising gate means selectively operable between a first condition in which said feed means is effective to move the sheets of material along a first path into the nip between said rollers in said folder means and a second condition in which said feed means is effective to move the sheets along a second path which bypasses the nip between said rollers in said folder means to thereby enable the sheets to pass through said assembly in an unfolded condition.

10. An assembly as set forth in claim 9 wherein said feed means includes conveyor means for moving said sheets along the second path and bypassing said trimmer means when said gate means is in the second condition.

ill. An assembly as set in claim wherein said trimmer means further comprises a fixed knife for cooperating with said single knife to effect a cutting of the folded sheets along their face portion, said fixed knife and said rollers being located with their longitudinal axes extending parallel to each other and inclined relative to a horizontal plane.

12. An assembly as set forth in claim wherein said first means is operable to move the leading edge portion of the sheets into engagement with said register surface with sufficient force to effect a buckling of the sheets and to move the buckled portion of the sheets into the nip in said folder means.

113. An assembly as set forth in claim 8 wherein said register means further includes a sheet support surface located immediately adjacent to said rollers and inclined relative to the horizontal plane at substantially the same angle as are said rollers, said register surface being located adjacent to a lower side of said support surface to engage a lowermost side edge portion of the sheets as the sheets enter the nip in said folder means.

14. An assembly as set forth in claim 13 wherein said register means further includes adjustment means for varying the position of said register surface upwardly and downwardly along said sheet support surface to enable said register surface to be used with sheets of different physical characteristics.

15. An assembly for folding a plurality of sheets along a predetermined fold line extending between side edge portions of the sheets in a generally parallel relationship with leading and trailing edge portions of the sheets, said assembly comprising a base, folder means operatively connected with said base for forming a fold in the sheets along the predetermined fold line, feed means operatively connected with said base for feeding the sheets to and from said folder means, said feed means and said folder means including a plurality of rollers cooperating to define a plurality of nips through which the sheets pass and which are inclined upwardly at an acute angle relative to a horizontal plane whereby one of the side edge portions of the sheets is below the other side edge portion of the sheets when the sheets pass through the nips defined by said rollers, adjustment means operatively connected with said rollers for varying the positions of said rollers relative to each other to thereby enable said assembly to fold varying numbers of sheets, register means operatively connected with said base for registering the sheets with the predetermined fold line extending generally parallel to the inclined nips defined by said rollers before the sheets pass through a nip defined by rollers of said folder means, said register means including a sheet supporting surface inclined relative to the horizontal plane at substantially the same acute angle as are the nips defined by said rollers, front register means for engaging the leading edge portion of sheets as they are moved along said inclined support surface under the influence of said feed means and for arresting movement of the leading edge portion of the sheets, means for adjusting the relative position of said front register means and said support surface to enable said front register means to be used for registering sheets of different lengths, side register means for engaging the lower side edge portion of sheets on said inclined support surface to maintain the predetermined fold line of the sheets generally parallel to the inclined nips defined by said rollers as the sheets enter one of the inclined nips, and means for adjusting the relative positions of said side register means and said support surface to enable said side register means to be used with sheets of different physical characteristics, said front and side register means cooperating with each other to position sheets on said inclined support surface in such an orientation that when the sheets pass through said one of the inclined nips a fold is formed along the predetermined fold line, and trimmer means operatively connected with said base for trimming the folded sheets to their final size with only a single cutting operation which is performed along the face portion of the folded sheets, said trimmer means comprising a fixed knife which is inclined at the same acute angle relative to the horizontal plane as are the nips defined by said rollers, a single movable knife which cooperates with said fixed knife, and means for reciprocating said single movable knife to trim the folded sheets to their final size with only one stroke of said single movable knife.

16. An assembly as set forth in claim 15 further comprising gate means selectively operable between a first condition in which said feed means is efi'ective to move the sheets of material along a first path into the nip between said rollers in said folder means and a second condition in which said feed means is effective to move the sheets along a second path which bypasses said trimmer means and the nip between said rollers in said folder means to thereby enable the sheets to pass through said assembly in a unfolded condition without being trimmed.

17. An assembly as set forth in claim 16 wherein said feed means is operable to move the leading edge portion of the sheets into engagement with said front register means with sufficient force to effect a buckling of the sheets along the predetermined fold line and to move the buckled portion of the sheets into the nip defined by the rollers of said folder means. 

1. An assembly for folding sheets along a predetermined fold line extending between side edge portions of the sheets in a generally parallel relationship with leading and trailing edge portions of the sheets, said assembly comprising a plurality of folder rollers cooperating to define a nip and having their longitudinal axes inclined relative to a horizontal plane whereby one side edge portion of the sheets is lower than the other side edge portion when the sheets pass between said folder rollers, feed means for moving the sheets to and from the nip formed by said folder rollers, and registering means for arresting movement of a leading edge portion of the sheets prior to movement of the sheets through the nip formed by the inclined folder rollers, for registering the sheets with the predetermined fold line extending generally parallel to the inclined longitudinal axes of said folder rollers, and for maintaining the predetermined fold line generally parallel to the inclined longitudinal axes of the folder Rollers as the sheets enter the nip formed by the folder rollers, said registering means including a sheet support surface inclined relative to the horizontal plane at substantially the same angle as are the inclined longitudinal axes of said folder rollers, said inclined support surface including a trailing edge portion disposed adjacent to the nip formed by said folder rollers, a leading edge portion spaced further from said folder rollers than said trailing edge portion of said inclined support surface, and upper and lower side edge portions extending between said leading and trailing edge portions of said inclined support surface, said leading and trailing edge portions of said inclined support surface having longitudinal axes extending generally parallel to the inclined longitudinal axes of said folder rollers, said registering means further including front register means having a front register surface extending substantially perpendicularly from said leading edge portion of said inclined support surface for arresting movement of the leading edge portion of sheets as they are moving along said inclined support surface under the influence of said feed means, and side register means including a side register surface extending substantially perpendicularly from said lower side edge portion of said inclined support surface at a location intermediate the longitudinally extending axes of the leading and trailing edge portions of said inclined support surface for engaging the lower side edge portion of the sheets at a location which is between the predetermined fold line and the leading edge portion of the sheets when the sheets are on said inclined support surface to maintain the predetermined fold line generally parallel to the longitudinal axes of said folder rollers as the sheets are fed to the nip formed by the folder rollers and adjustment means for moving said side register surface relative to said support surface to adjust said side register means to position sheets of different physical characteristics on said inclined support surface in such an orientation that as the sheets pass through the nip formed by the inclined folder rollers a fold is formed along the predetermined fold line.
 2. An assembly as set forth in claim 1 wherein said feed means comprises a plurality of inclined feed rollers positioned with their longitudinal axes extending generally parallel to the inclined longitudinal axes of said folder rollers.
 3. An assembly as set forth in claim 1 wherein said adjustment means includes means for moving said side register surface along a path extending generally parallel to the inclined longitudinal axes of said folder rollers.
 4. An assembly as set forth in claim 1 wherein said feed means is operable to move the leading edge portion of the sheets into engagement with said front register means with sufficient force to effect a buckling of the sheets along the predetermined fold line and to move the buckled portion of the sheets into a nip defined by said folder rollers.
 5. An assembly as set forth in claim 1 further including cutter means for trimming the folded sheets along only their face edge portion.
 6. An assembly as set forth in claim 5 wherein said cutter means includes only one movable knife and means for reciprocating said one movable knife through a stroke having a longitudinal axis extending generally perpendicular to the inclined longitudinal axes of said folder rollers.
 7. An assembly as set forth in claim 6 wherein said cutter means further comprises a fixed knife for cooperating with said one movable knife, said fixed knife extending generally parallel to the inclined longitudinal axes of said folder rollers.
 8. An assembly for folding sheets along a predetermined fold line extending between side edge portions of the sheets in a generally parallel relationship with leading and trailing edge portions of the sheets, said assembly comprising a base, folder means operatively connected with said base and rollers having theIr axes inclined relative to a horizontal plane and defining a nip for forming a fold in the sheets along the predetermined fold line when the sheets pass through the nip, feed means operatively connected with said base having first means for feeding sheets to said folder means, register means for positioning the sheets with the predetermined fold line in a predetermined relationship with the nip in said folder means to thereby facilitate the forming of the fold along the predetermined fold line, said register means including a register surface positioned to be engaged by an edge portion of the sheets as the sheets enter the nip in said folder means to position the sheets in the predetermined relationship with the nip in said folder means, and trimmer means operatively connected with said base for trimming the folded sheets to their final size with a single cutting operation which is performed only along the face edge portion of the folded sheets, said feed means including second means for feeding the folded sheets from said folder means to said trimmer means, said trimmer means including only a single movable knife and means for reciprocating said single knife relative to said base to trim the folded sheets to their final size with only one stroke of said knife.
 9. An assembly as set forth in claim 8 further comprising gate means selectively operable between a first condition in which said feed means is effective to move the sheets of material along a first path into the nip between said rollers in said folder means and a second condition in which said feed means is effective to move the sheets along a second path which bypasses the nip between said rollers in said folder means to thereby enable the sheets to pass through said assembly in an unfolded condition.
 10. An assembly as set forth in claim 9 wherein said feed means includes conveyor means for moving said sheets along the second path and bypassing said trimmer means when said gate means is in the second condition.
 11. An assembly as set in claim 8 wherein said trimmer means further comprises a fixed knife for cooperating with said single knife to effect a cutting of the folded sheets along their face portion, said fixed knife and said rollers being located with their longitudinal axes extending parallel to each other and inclined relative to a horizontal plane.
 12. An assembly as set forth in claim 8 wherein said first means is operable to move the leading edge portion of the sheets into engagement with said register surface with sufficient force to effect a buckling of the sheets and to move the buckled portion of the sheets into the nip in said folder means.
 13. An assembly as set forth in claim 8 wherein said register means further includes a sheet support surface located immediately adjacent to said rollers and inclined relative to the horizontal plane at substantially the same angle as are said rollers, said register surface being located adjacent to a lower side of said support surface to engage a lowermost side edge portion of the sheets as the sheets enter the nip in said folder means.
 14. An assembly as set forth in claim 13 wherein said register means further includes adjustment means for varying the position of said register surface upwardly and downwardly along said sheet support surface to enable said register surface to be used with sheets of different physical characteristics.
 15. An assembly for folding a plurality of sheets along a predetermined fold line extending between side edge portions of the sheets in a generally parallel relationship with leading and trailing edge portions of the sheets, said assembly comprising a base, folder means operatively connected with said base for forming a fold in the sheets along the predetermined fold line, feed means operatively connected with said base for feeding the sheets to and from said folder means, said feed means and said folder means including a plurality of rollers cooperating to define a plurality of nips through which the sheets pass and which are inclined upwardly at an acute angle relative to a horizontal plane whereby one of the side edge portions of the sheets is below the other side edge portion of the sheets when the sheets pass through the nips defined by said rollers, adjustment means operatively connected with said rollers for varying the positions of said rollers relative to each other to thereby enable said assembly to fold varying numbers of sheets, register means operatively connected with said base for registering the sheets with the predetermined fold line extending generally parallel to the inclined nips defined by said rollers before the sheets pass through a nip defined by rollers of said folder means, said register means including a sheet supporting surface inclined relative to the horizontal plane at substantially the same acute angle as are the nips defined by said rollers, front register means for engaging the leading edge portion of sheets as they are moved along said inclined support surface under the influence of said feed means and for arresting movement of the leading edge portion of the sheets, means for adjusting the relative position of said front register means and said support surface to enable said front register means to be used for registering sheets of different lengths, side register means for engaging the lower side edge portion of sheets on said inclined support surface to maintain the predetermined fold line of the sheets generally parallel to the inclined nips defined by said rollers as the sheets enter one of the inclined nips, and means for adjusting the relative positions of said side register means and said support surface to enable said side register means to be used with sheets of different physical characteristics, said front and side register means cooperating with each other to position sheets on said inclined support surface in such an orientation that when the sheets pass through said one of the inclined nips a fold is formed along the predetermined fold line, and trimmer means operatively connected with said base for trimming the folded sheets to their final size with only a single cutting operation which is performed along the face portion of the folded sheets, said trimmer means comprising a fixed knife which is inclined at the same acute angle relative to the horizontal plane as are the nips defined by said rollers, a single movable knife which cooperates with said fixed knife, and means for reciprocating said single movable knife to trim the folded sheets to their final size with only one stroke of said single movable knife.
 16. An assembly as set forth in claim 15 further comprising gate means selectively operable between a first condition in which said feed means is effective to move the sheets of material along a first path into the nip between said rollers in said folder means and a second condition in which said feed means is effective to move the sheets along a second path which bypasses said trimmer means and the nip between said rollers in said folder means to thereby enable the sheets to pass through said assembly in a unfolded condition without being trimmed.
 17. An assembly as set forth in claim 16 wherein said feed means is operable to move the leading edge portion of the sheets into engagement with said front register means with sufficient force to effect a buckling of the sheets along the predetermined fold line and to move the buckled portion of the sheets into the nip defined by the rollers of said folder means. 